Failed -remote 39-flashing Lock Flag Is Locked. Please Unlock It First 39-- |best| Info
For MediaTek and Spreadtrum (Unisoc) devices, replacing the bootloader with an engineering version can bypass the lock flag check.
The error remote 39 indicates that your tool tried to force the door open without turning the key first. The controller responded with a NACK (Negative Acknowledgment) and the status code 39, signifying a permissions violation. For MediaTek and Spreadtrum (Unisoc) devices, replacing the
Lock and unlock the bootloader | Android Open Source Project For MediaTek and Spreadtrum (Unisoc) devices